Slab Construction-30 Years Later

A residential foundation repair project is described. Poor construction of the original foundation, consisting of slab on grade and perimeter grade beams, resulted in damage in the form of settlement, cracking, misalignment of doors, and plumbing leaks. The initial remediation plan involved construction of underpinning piers. Pier installation beneath perimeter grade beams was accomplished, however it was discovered that interior slabs that were designed to be 6-inches thick were in fact only 2-inches thick and not properly reinforced. A 2-stage repair was used consisting of grout injection to increase the effective slab thickness followed by mudjacking to establish the original slab elevations. This process was highly successful and suggests an approach for addressing similar residential foundation repairs.